Additive-containing polymeric compositions and methods of making the same

ABSTRACT

Polymeric compositions include a nonaqueous additive system having dispersant-coated pigments physically dispersed in a liquid nonaqueous polymeric carrier which may be added directly to a melt flow of a polymeric host material. The additive system employed in the polymeric systsms is most preferably in the form of a particulate paste which can be added in metered amounts (dosed) to a melt flow of the polymeric host material prior to being spun into filaments. By providing a number of additive systems having a number of different additive attributes, and controllably dosing one or more into the melt flow of host polymeric material, shaped objects of the polymeric material (e.g., melt-spun filaments) having different additive attributes may be produced on a continuous basis without shutting down the shaping operation.

CROSS-REFERENCE TO RELATED APPLICATION

This application is related to, and claims domestic priority benefitsunder 35 USC §119(e) from, U.S. Provisional Application Ser. No.60/012,794 filed on Mar. 4, 1996, the entire content of which isexpressly incorporated hereinto by reference.

FIELD OF INVENTION

The present invention relates generally to the field of thermoplasticpolymeric materials containing one or more additives. In preferredexemplary embodiments, the present invention relates to syntheticfilament additives (e.g., colorants) and to methods for incorporatingsuch additives in melt flows of filament-forming thermoplastic polymericmaterials prior to melt-spinning to form synthetic filaments therefrom.

BACKGROUND AND SUMMARY OF THE INVENTION

The incorporation of additives in so-called "neat" thermoplasticpolymeric host materials (that is, polymeric materials containing noadditives) so as to achieve desired physical properties is well known.Thus, the art has conventionally incorporated colorants, stabilizers,delusterants, flame retardants, fillers, antimicrobial agents,antistatic agents, optical brighteners, extenders, processing aids andother functional additives into polymeric host materials in an effort to"engineer" desired properties of the resulting additive-containingpolymeric host material. Such additives are typically added any timeprior to shaping of the polymeric material, for example, by spinning ormolding (e.g., extrusion, injection, or blow-molding) operations.

The incorporation of colorant additives in filaments formed bymelt-spinning a polymeric material has presented unique challenges. Forexample, the amount of particulate pigment dispersed in a concentratewhich is added to the polymeric material must be sufficiently high toimpart satisfactory color density, but must not be so high as tointerrupt the spinning process. One prior proposal for incorporatingcolorant additives in thermoplastic polymeric materials is disclosed inU.S. Pat. No. 5,236,645 to Frank R. Jones on Aug. 17, 1993 (the entirecontent of which is expressly incorporated hereinto by reference).

According to the Jones '645 patent, additives are introduced into athermoplastic melt by feeding at least one additive in an aqueousvehicle containing a dispersant to form an aqueous additive stream to avented extruder which is extruding a thermoplastic. The aqueous portionof the aqueous additive stream is thereby volatilized within theextruder and is removed therefrom via an extruder vent. As a result, asubstantially homogeneous system containing the thermoplastic,dispersant and the additive is obtained which may thereafter be spuninto a filament by melt-extrusion through filament-forming orifices in aspinneret associated with a spin pack assembly.

Although the techniques disclosed in the Jones '645 patent are entirelysatisfactory, some further improvements to incorporating additives in amelt flow of thermoplastic polymeric materials would be desirable. Forexample, it would especially be desirable if the additive stream wasnon-aqueous as this would obviate the need for a vented extruder (i.e.,since a volatilized aqueous portion of the additive stream would notthen need to escape prior to melt-spinning). Furthermore, it is entirelypossible that a non-aqueous additive stream could be introducedphysically near or into the spin pack assembly where it can be mixedwith a melt flow of the polymeric material immediately upstream of thespinneret orifices (and preferably downstream of the polymer filtersection of the spin pack assembly) thereby bypassing the extruder. Sucha possibility would then allow additive concentration and/or types to bechanged on a continuous basis to produce sequential lengths of melt-spunfilaments having desired, but different, properties and/orcharacteristics. That is, the upstream processing equipment, forexample, the extruders and process piping, which supply the polymerichost material to the spin pack assembly would not necessarily need to beshut down for purposes of cleaning. Furthermore, by introducing anon-aqueous additive stream directly into the spin pack assembly, theflushing time would be relatively short thereby allowing, for example,quick color changes to occur from one filament production batch toanother. It is towards providing such improvements that the presentinvention is directed.

Broadly, the present invention is embodied in a nonaqueous additiveconcentrate system for thermoplastic polymeric host materials which maybe added directly to a melt flow of the polymeric material in meteredamounts. More specifically, the additive concentrate system according tothe present invention includes a filament additive which is dispersed ina liquid or liquefied nonaqueous carrier. The filament additive may,during use, be in the form of a solid particulate or a liquid. When asolid particulate is used, the additive system of this invention mostpreferably also includes a dispersant which coats the particulateadditive. The additive concentrate system according to this invention ismost preferably in the form of a flowable paste which can be added inmetered amounts (dosed) to a melt flow of the polymeric material priorto being spun into filaments, for example near or into the spin packassembly upstream of the assembly's filament-forming spinneret orifices.

In such a manner, therefore, synthetic filament batches having differentadditives may be produced sequentially on a continuous basis withoutcostly equipment downtime. That is, the same spin pack assembly may beused to produce a first batch of filaments containing one type ofadditive during one production interval, and then used to produce asecond batch of filaments containing a second type of additive during asucceeding production interval by changing the additive which isintroduced into the filament-forming melt. Moreover, the time intervalneeded to change between different additives is relatively short sincethe additive system is most preferably introduced into the melt flownear or into the spin pack assembly which in turn reduces significantlythe time needed to flush residual additive incorporated into the firstbatch of filaments. Production of different additive-containingfilaments (e.g., filaments containing different colorants) is nowpossible in a relatively short period of time without stopping filamentwinding.

Thus, another aspect of this invention involves a method of continuouslyproducing sequential lengths of different additive-containing filamentsby continuously supplying a melt-spinnable polymeric host material toorifices of a spinneret and, during a first time interval, controllablydosing a concentrate system having one additive into the polymericmaterial to form a first polymeric mixture which is extruded through thespinneret orifices. Subsequently, during a second time interval, anotherconcentrate system containing a different additive is controllably dosedinto the polymeric material without disrupting the continuous supply ofpolymeric material to the spinneret orifices to form a second polymericmixture which is extruded through the spinneret orifices.

During the change of additive concentrate, an intermediate time intervalwill be needed in order to flush the spinneret of residual amounts ofthe first additive concentrate. Thus, during the intermediate timeintervals, an intermediate length of filaments will be produced whichwill change over the filament length from containing all of the firstadditive concentrate to containing all of the second additiveconcentrate. This intermediate length of filaments produced according tothe present invention will be handled separately from the first andsecond lengths of production filaments. However, the amount of suchintermediate length of filaments will be relatively small since, asnoted above, the time interval needed to flush the spinneret of residualamounts of the first additive concentrate is relatively short.

Other advantages ensue from introducing the additive concentrate systemto the polymeric host material within the spin pack assembly. Forexample, the spin pack assembly and its associated spinneret orificesmay be so designed to form melt-spun multicomponent filaments (e.g.,filaments having multiple domains of different polymer blends, colorantsand/or other additives) such as those filaments disclosed in U.S. Pat.No. 5,162,074 to Hills (the entire content of which is expresslyincorporated hereinto by reference) by splitting a melt-flow ofpolymeric host material into two or more subflows within the spin packassembly. According to the present invention, therefore, the additiveconcentrate system may be introduced into the spin pack assembly andmixed with one or more of such subflows of polymeric host materialwithout being mixed with other subflows so as to form multicomponentfilaments. Therefore, while the discussion which follows emphasizes theproduction of filaments in which the additive concentrate system issubstantially homogeneously mixed through the filament cross-section, itwill be understood that the present invention is likewise applicable tothe formation of multicomponent filaments whereby the additiveconcentrate system is substantially homogeneously mixed throughout oneor more multiple polymeric domains in the filament cross-section withoutbeing present in the other domain(s) (e.g., as in core-sheath filaments,pie wedge filaments, side-by-side filaments and the like).

As noted above, significant processing flexibility ensues according tothe present invention. Processing flexibility is the result of at leasttwo features of the present invention. First, additive concentratesystems can be mixed above the spinneret with either the entire hostpolymer or only a portion of the host polymer. For example, a functionaladditive (e.g., an antistatic agent) concentrate system might be mixedwith only a third of the host polymer such that a third of the filamentsspun contain the antistatic agent and the remaining two-thirds do not.

Second, two or more additive concentrate systems can be mixed with thehost polymer above the spinneret to achieve a single attribute in thefiber that is spun. For example, a yellow additive concentrate systemand a blue additive concentrate system can be concurrently mixed withhost polymer above the spinneret to provide a green fiber when themixture is spun. There is no theoretical limit for the number ofadditive concentrate systems that can be mixed with the host polymerabove the spinneret. The number of additive concentrate systems islimited only by the space available to inject the systems into the line.It is contemplated that the host polymer might also contain someadditive prior to mixing above the spinneret.

These two features of the present invention are not mutually exclusiveand great flexibility ensues from combining them. Using color as anexample, either single color or multicolor yarn can be spun using thepresent invention. Single color yarn may be spun by mixing one or morecolor additive concentrate systems (e.g., a yellow system and bluesystem as exemplified above) with the entire host polymer such that aone color yarn (e.g., a multifilamentary yarn containing only greenfilaments) results.

Multicolor yarn (e.g., heather yarn) may be spun by selectively coloringseparated portions of the host polymer and keeping each separatedportion segregated until spun. For example, a portion of the hostpolymer might be colored with both the yellow and the blue additivesystems to produce green filaments. Another portion of the host polymermight be colored with a red additive system to produce red filamentswhich are spun concurrently with the green filaments. The resultingmultifilamentary yarn will therefore exhibit a heathered color due tothe combination of individual red and green filaments present in theyarn.

The concepts above apply also to the spinning of filaments havingmultiple cross-sectional domains, such as core-sheath filaments, piewedge filaments, side-by-side filaments and the like. Thus, formultidomain filaments, the additive concentrate system may be mixed withone or more split flows of the host polymer and then recombined with theremainder of the host polymer flow to achieve filaments having theadditive present only in one or more of the cross-sectional domains.

When the additive is a colorant, therefore, a virtually unlimited numberof multicolored, multidomain filaments can be produced. For example,only the core of a core-sheath filament may include one or more colorantadditives which imparts to the fiber a color attribute that is visiblyperceptible through the uncolored sheath. In this regard, it has beenfound that colorant additive(s) contained only in the core of acore-sheath multidomain filament results in a color intensity that isachieved with reduced colorant loading levels (e.g., between about 5 toabout 10% less) as compared to filaments having the same colorantadditive(s) homogeneously dispersed throughout the entire filamentcross-section to achieve comparable color intensity.

Alternatively or additionally, the colorant additive may be present inthe sheath of a core-sheath filament so as to achieve a color effectthat is a combination of the core and sheath colors. Thus, byselectively choosing and incorporating colorants into the core and/orsheath, virtually any color attribute can be achieved for the resultingfilament. Some particular combinations of colorants in both the core andsheath of a core-sheath filament may not necessarily result in a "pure"color combination of such colorants being realized for the filament.That is, the additive/subtractive effects of colorants in the core andsheath of core-sheath filaments are relatively complex and sometimescannot be predicted with absolute certainty. However, routineexperimentation with colorants in the core and/or sheath of core-sheathfilaments will result in virtually an unlimited number of desiredfilament color attributes being obtained.

Other multiple domain filament combinations are envisioned, such asside-by-side domain filaments having different color attributes in eachof the sides or pie wedge filaments whereby one or more of the wedgeshave the same or different color attributes. Such multiple domainfilaments may be usefully employed to form heather yarns since the coloradditive-containing domains will visually present themselves atdifferent locations along the length of the filaments when twisted(e.g., as may occur during yarn processing). Furthermore, the colorantsand domains in which such colorants are present can be selected toachieve filaments which macroscopically appear to be uniformly colored.

Furthermore, although the additive concentrate systems of this inventionmay be metered (dosed) into the host polymer (whether in its entirety orin one or more of its split flows) at a substantially constant rate,periodic or continual variance of the dose rate is also envisioned.Thus, as noted briefly above, when changing from one filament recipe toanother, one or more of the additive concentrates will need to be variedin order to switch filament production from a former recipe to the thencurrent recipe. A random or constant dosage rate variance can also bepracticed, however, in which case the resulting filaments will have moreor less of the additive distributed along its length. When the additiveis a colorant, such a technique allows filaments to be formed having aslub-like color appearance along its axial length which may be employed,for example, to produce yarns having a striated or marbled impression.

These and other aspects and advantages of this invention will becomemore clear after careful consideration is given to the followingdetailed description of the preferred exemplary embodiments thereof.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING

Reference will hereinafter be made to the accompanying drawing whereinFIG. 1 is a schematic view of a filament melt-spinning apparatus inwhich the additive system of this invention may be added to a melt flowof polymeric material prior to spinning.

DETAILED DESCRIPTION OF THE PREFERRED EXEMPLARY EMBODIMENTS

To promote an understanding of the principles of the present invention,descriptions of specific embodiments of the invention follow andspecific language describes the same. It will nevertheless be understoodthat no limitation of the scope of the invention is thereby intended,and that such alterations and further modifications, and such furtherapplications of the principles of the invention as discussed arecontemplated as would normally occur to one ordinarily skilled in theart to which the invention pertains.

Thus, for example, while reference has been, and will hereinafter be,made to melt-spinning of filaments, it will be understood that otheroperations which serve to shape a melt of a polymeric material to afinal form (e.g., extrusion or injection molding, blow-molding or thelike) are contemplated. Furthermore, for ease of reference, thediscussion which follows will emphasize the presently preferredembodiment of the invention in terms of incorporating colorants intopolymeric materials, but the present invention can likewise be employedto incorporate virtually any other conventional additive as may bedesired. In this regard, the term "pigment" as used herein and in theaccompanying claims is meant to refer to virtually any material that maybe added physically to a polymer melt flow, and thus genericallyencompasses colorant pigments which will be emphasized in the discussionwhich follows. Thus, suitable pigments which may be employed in thepractice of this invention include solid and liquid colorants,stabilizers, delusterants, flame retardants, fillers, antimicrobialagents, antistatic agents, optical brighteners, extenders, processingaids and other functional additives.

As used herein and in the accompanying claims, the term "color" includesMunsell Values between about 2.5/ to about 8.5/ and Munsell Chromasgreater than about /0.5. (Kelly et al, The ISCC-NBS Method ofDesignating Colors and a Dictionary of Color Names, National Bureau ofStandards Circular 553, pp. 1-5 and 16 (1955), incorporated hereinto byreference.)

The host polymer in which the additive concentrate system of thisinvention may be incorporated includes any synthetic thermoplasticpolymer which is melt-spinnable. Exemplary polymers are polyamides suchas poly(hexamethylene adipamide), polycaprolactam and polyamides ofbis(4-aminocyclohexyl) methane and linear aliphatic dicarboxylic acidscontaining 9, 10 and 12 carbon atoms; copolyamides; polyester such aspoly(ethylene)terephthalic acid and copolymers thereof; polyolefins suchas polyethylene and polypropylene; and polyurethanes. Both heterogeneousand homogeneous mixtures of such polymers may also be used.

I. ADDITIVE CONCENTRATE PREPARATION

As noted above, the additive concentrate system employed in the practiceof the present invention is a dispersion or solution of pigment in anonaqueous liquid or liquefied polymeric carrier. The pigment may be asolid particulate (e.g., a colorant) which is coated with a dispersantfor physical dispersion in the carrier material. Alternatively, thepigment may be in a form which is soluble with the carrier, in whichcase the dispersant is not necessarily employed. Thus, the pigment mayhomogeneously be suspended and/or solubilized in the carrier.

Although a variety of pigments may be employed in the practice of thepresent invention, it is presently preferred that the pigment is aparticulate colorant pigment having a mean particle size of less than 10μm, preferably less than about 5 μm, and most preferably between 0.1 μmto about 2 μm.

If present, the preferred dispersants which may be employed in thepractice of this invention are the water soluble/dispersible polymers asdescribed in U.S. Pat. No. 3,846,507 (the entire content of which isexpressly incorporated hereinto by reference). One particularly usefuldispersant in this class is a copolymer ofcaprolactam/hexamethylenediamine/isophthalic acid/sodium salt ofsulfoisophthalic acid having a molecular weight of about 7,000, aspecific gravity (H₂ O=1) of about 1.1, a solubility in water of about25% at 20° C. This preferred water soluble/dispersible polyamidecopolymer dispersant is manufactured by BASF Corporation and willhereinafter be referenced as "C-68".

Other useful dispersants that may be employed in the practice of thisinvention are water soluble/dispersible polyesters. One particularlypreferred polyester which is completely dispersible in water iscommercially available from Eastman Chemical Products, Inc., Kingsport,Tenn., under the product name "LB-100". This preferred watersoluble/dispersible polyester has a specific gravity (H₂ O=1) of about1.08, and is available commercially as a 30% solution of the polyesterin water.

Other water soluble/dispersible polymers that may be useful in thepractice of the present invention include, but are not limited to otherwater soluble/dispersible polyamides and copolymers thereof, watersoluble/dispersible polyesters and copolymers thereof, watersoluble/dispersible vinyl polymers and copolymers thereof, watersoluble/dispersible alkylene oxide polymers and copolymers thereof andwater soluble/dispersible polyolefins and copolymers thereof, as well asmixtures of the same. Other dispersants, like monomeric dispersants, maybe suitable for use with the present invention.

One presently preferred technique for producing the additive dispersionof this invention uses as a starting material the aqueous dispersionformed according to the above-referenced Jones '645 patent. The aqueousdispersion may then be bead-milled and subjected to a spray dryingoperation so as to remove the aqueous component. The resultingdispersant-coated pigment granules (hereinafter more simply referred toas the "dispersible pigment granules") are in powder form and have anaverage particle size of greater than about 5 μm. The dispersiblepigment granules may then be mixed with a nonaqueous liquid polymericcarrier material. When dispersed into the polymeric host material, thedispersible pigment granules will break apart into average particlesizes of about 1 μm or less. In this way, maximum pigment loadings maybe achieved without unduly increasing viscosity of the paste, while atthe same time allowing the dispersible pigment granules to readilydisperse in the polymeric host material at a size which does not affectadversely the spinning operation.

The carrier material can be virtually any material that is liquid at orbelow melt-spinning temperatures of the polymeric host material.Preferably, the carrier material is a polyamide or a polyester. Thecarrier material must also be compatible with the thermoplasticpolymeric host material. For example, when providing an additiveconcentrate system for incorporation into a nylon-6 polymeric hostmaterial, the presently preferred carrier is polycaprolactone since itis liquid at room temperatures (20° C.). However, carriers that may beliquefied at elevated temperatures (e.g., less than about 200° C.) arealso useable in the practice of this invention. For example, whenproviding an additive concentrate system for incorporation into anylon-6 polymeric host material, it is also possible to use copolyamideshaving a melting point of less than about 200° C. One particularlypreferred class of such copolyamides is commercially available under thetrade name Vestamelt copolyamides from Huls America Inc. of Piscataway,N.J., with Vestamelt 722 being particularly preferred.

One alterative technique to make the additive concentrate systemaccording to this invention involves mixing the pigment, carrier and, ifpresent, dispersant to form a nonaqueous paste in a one-step processthereby eliminating the need to prepare an aqueous dispersion which issubsequently spray dried. It is preferred that the dispersant, ifpresent, and the carrier be premixed prior to addition of the pigment.The mixture may then be milled so as to obtain a paste which can beintroduced directly into a melt flow of the polymeric host material.

The additive concentrate system of this invention may also be preparedby combining the pigment and the dispersant in a high-intensity mixer(e.g., a Henschel FM series mixer available commercially from HenschelMixers America, Inc. of Houston, Tex.) until they are intimately mixed.Thereafter, the shear imparted by the mixer is reduced, and the requiredmass of carrier is added to yield the additive concentrate of thisinvention in paste form.

The dispersants that may be employed in the one-step technique, inaddition to those described above, include polyethylene glycol p-octylphenyl ether (Triton X-100), polyoxypropylene/ethylene block copolymers(Pluronic 25R2), alkoxylated diamines (Tetronic 150R1), sodium laurylsulfate and cationic dispersants (VariQuat). The dispersant (i.e., thenon-carrier material), if present, is present in the additiveconcentrate system in an amount between about 5 to about 100 wt. % basedon the weight of the pigment, and more preferably, between about 40 toabout 100 wt. %.

However formed, the additive concentrate system is most preferably inthe form of a flowable paste having a viscosity during introduction intothe polymeric host material ranging between about 500 cP to about500,000 cP, and most preferably between about 1,500 cP to about 100,000cP, at a temperature between about 20° C. to about 200° C. Thedispersible additive may be maintained to within an acceptable viscosityrange by application of heat (e.g., by keeping the dispersible additivein a suitable storage vessel which is jacketed with electricalresistance heaters and/or a heat transfer medium).

The additive concentrate system preferably contains pigment in an amountbetween about 5 to about 75 wt. %, more preferably between about 10 toabout 65 wt. % based on the weight of the additive concentrate system.The additive concentrate system (the dispersible additive) itself isincorporated into the polymeric host material at levels between about0.01 to about 15 wt. %, more preferably between about 0.05% and 10.0 wt.% based on the total weight of the polymeric host material and additiveconcentrate system. When spray dried dispersible pigment granules areemployed, they will preferably be present in the paste (that is, thedispersible pigment granules and the carrier material) so as to providea solids content in the paste of at least about 50 wt. %, and morepreferably at least about 57 wt. % or greater.

II. FILAMENT PRODUCTION

Accompanying FIG. 1 schematically depicts a filament spinning operation10 by which additive concentrate systems may selectively be mixed with amelt flow of polymeric host material discharged from a conventionalscrew extruder 12 and supplied to an inlet of the spin pack assembly 14.More specifically, the polymeric host material is introduced into theupstream polymer filter section 14a of the spin pack assembly beforebeing extruded through orifices in the spinneret 14b to formadditive-containing filaments 16. Prior to reaching the spinneret 14b,the polymeric host material may be distributed by a plurality of thindistribution plates 14c in accordance with the above-noted U.S. Pat. No.5,162,074 to William H. Hills, which may or may not have one or morestatic mixing plates, for example, as disclosed in U.S. Pat. No.5,137,369 to John A. Hodan (the entire content of which is expresslyincorporated hereinto by reference).

Batches of the additive concentrate systems in paste form arerespectively held within portable tanks 18a-18d. In the accompanyingFIG. 1, tanks 18a-18d are shown supported on wheeled carts 20a-20d,respectively, so as to permit each of the tanks 18a-18d to be replacedeasily with stand-by tanks containing a fresh supply of the same ordifferent additive concentrate system. However, other means can beemployed which allow the tanks 18a-18d to be portable, such as in-groundor overhead conveyance systems, cranes and the like. Preferably, theadditive concentrate system contained in each of the tanks 18a-18d isdifferent--that is, tanks 18a-18d may each contain a different pigmentor pigment mixture so that selective incorporation of each will resultin the desired properties being achieved for the filaments 16.

Specifically, the tanks 18a-18c may each respectively containdispersible colorant pigments corresponding to selected colors such asaqua, magenta and yellow, while tank 18d may have a specially formulatedtint color (e.g., white, black or the like) to achieve the desired colorhue, chroma and/or intensity. The differently colored additiveconcentrates held within the tanks 18a-18d may thus be volumetricallydosed or mixed with the polymeric host material so as to achieve avirtually unlimited number of resulting colors of the melt-spunfilaments 16. In a like manner, other filament properties may be"engineered" by selective incorporation of other non-colorant pigments.

The carts 20a-20d also support a primary pump 22a-22d and a meteringpump 24a-24d, respectively. The pumps 22a-22d and 24a-24d are mostpreferably gear-type pumps which serve to force the additive concentratesystem paste through respective supply lines 26a-26d to the spin packassembly 14. More specifically, the primary pumps 22a-22d serve tomaintain a relatively constant input pressure to the immediatelydownstream respective metering pump 24a-24d. The primary pumps 22a-22dare therefore relatively larger capacity as compared to their respectivedownstream metering pump 24a-24d.

The additive concentrate system paste within each of the tanks 18a-18dis maintained under constant agitation in order to prevent sedimentationof the pigment therein. Such agitation may be accomplished by amotor-driven mixer 26a-26d and/or via recycle lines 28a-28d (and/orlines 30a-30d). Of course, if the pigment is in solution with thecarrier, then such agitation may not be needed.

The metering pumps 24a-24d are variable speed so as to achieve variablevolumetric outputs within their respective capacity range statedpreviously. The speed of the metering pumps 24a-24d is most preferablycontrolled by a logic programmable controller LPC. Specifically, for agiven "recipe" (for example, a desired color for the pigmented filaments16) input into the controller LPC, appropriate outputs will be issued toone or more of the metering pumps 24a-24d to cause them to operate at aspeed to achieve a desired volumetric output for their particulardispersible additive. Thus, it will be recognized that for certaindesired colors, some but not all of the metering pumps 24a-24d will besupplying paste from their respective tanks 18a-18d to the spin packassembly 14 and/or may be operated at different speeds to achievedifferent volumetric outputs. Suffice it to say, that by selectivelycontrolling the operation of the metering pumps 24a-24d and, whenoperated, their respective speed (and hence their respective volumetricoutputs), selective volumetric paste doses can be continuously suppliedto the spin pack assembly 14 where the respective additive concentratesystems will be homogeneously mixed with the melt flow of polymeric hostmaterial being fed by the extruder 12 via line 32.

The respective speed of one or more of the metering pumps 24a-24d mayalso be varied continually to thereby respectively vary the volumetricdose of one or more of the colorant systems over time. Such speed (dose)variance will thereby cause more or less additive concentrate systembeing incorporated into the filament per unit time where results in afilament having varying amounts of the additive per unit length. In thecontext of color additives, such speed variance may be employed so as toform filaments having a randomly striated or marbled color appearance.

The additive concentrate pastes from lines 26a-26d are most preferablyintroduced directly into the spin pack assembly 14 at a locationcorresponding to the distribution/mixing section 14c--that is, at alocation downstream of the polymer filter 14a, but upstream of thespinneret 14b. In this manner, a relatively quick additive changebetween successive batches of filaments 16 is possible (i.e., to allowfor changes in additive recipe to be realized from one filament batch toanother). In addition, such an inlet location for the additiveconcentrates also allows for a wide range of processing flexibility tobe achieved. For example, the additive pastes from tanks 18a, 18b, 18cand/or 18d may be mixed with the entirety of polymeric host materialsupplied via line 32 so that all of the filaments 16 have the samecolor. Alternatively, the distribution/mixing section 14c of the spinpack assembly 14 may be so provided to split the flow of polymeric hostmaterial with one or more of the additive concentrate pastes being mixedwith one or more of such split flows to achieve, for example, multipledifferently colored filament groups which may remain segregated to formsingle color yarns or may be combined to form multicolor yarns, such asin a heather yarn. In addition, several additives may be mixed with thehost polymer so that, for example, single color yarns having multipleadditive concentrations therein may be produced from the same spinningequipment. Similarly, one or more additive concentrate pastes may bemixed with split flows of polymeric host material within thedistribution/mixing section 14c of the spin pack assembly 14 to achievemultifilamentary yarns having differently colored filaments (e.g., asmay be desired to produce yarns having a heathered appearance).

Although accompanying FIG. 1 (and the description above) shows theadditive concentrate system pastes being preferably introduced into themelt flow of polymeric host material directly into the spin packassembly 14 at a location between the polymer filter section 14a and thespinneret 14b, it will be understood that the pastes may be incorporatedinto the melt flow of polymeric host material at any location upstreamof the spinneret 14b. Thus, for example, the additive system pastes maybe incorporated into the melt flow of polymeric host material by feedingthrough an injection port associated with the extruder 12 and/or througha port in line 32. Thus, for example, the additive system pastes may beintroduced to the polymeric host material at or downstream of theextruder throat, but upstream of the spinneret 14b.

Different batches of colored filaments 16 may thus be producedcontinuously by simply changing the recipe in the controller LPC andallowing a sufficient time interval to elapse to ensure that anyresidual amounts of the additive concentrate system pastes associatedwith the prior recipe have been purged from the spin pack assembly 14.While some off-specification filament will ensue during the change-overto the new recipe, its economic impact is small by comparison tocomplete shut-down of the spinning operation. Furthermore, sincerelatively small amounts of the additive concentrate system pastes willresidually be present in the spin pack assembly 14 at the time of recipechange-over, only a relatively short time interval is needed to purgethe spin pack assembly of the prior additive recipe and begin producingfilaments pigmented with the new recipe.

III. EXAMPLES

The following nonlimiting examples will provide a further understandingof this invention.

In this regard, carpet samples formed of filaments colored in accordancewith the present invention and filaments colored in accordance withconventional extruder melt-blending techniques were tested according tothe following procedures and, where applicable, a subjective ratingscale of between 1 to 5 was utilized (5 being the best rating):

Yarn Degradation: Data representative of yarn strength/elongation beforeand after 100, 200 and 300 hours ultraviolet radiation exposureaccording to AATCC Test Method 16-1993, Option E.

Colorfastness: Yarn color/visual data after 100, 200 and 300 hoursultraviolet radiation exposure according to AATCC Test Method 16-1993,Option E.

Taber Abrasion Test: ASTM D3884-92.

Crocking: AATCC Test Method 8-1989.

Exposure to 50% Bleach: Carpet samples were cut into two 4.5"×9"squares. 25 ml of a bleach solution containing about 2.6% sodiumhypochlorite (50% Clorox® brand bleach and water) was poured into thecenter of one sample to form a test region approximately 2" in diameter.The sample was allowed to air dry for 24 hours after which it was rinsedwith a hot detergent/water solution containing 12 parts water and 1 partdetergent. The rinsed sample was air dried for 24 hours after which itwas visually rated on a scale of 1 to 5 against the untreated sampleusing AATCC Gray Scale in a Macbeth light booth (daylight setting).

Visual Grades After Exposure to Ozone: AATCC Test Method 129-1990.

Visual Grades After Exposure to NO₂ : AATCC Test Method 1641992.

Dry Heat Exposure: Samples are heated in a laboratory oven (1600 Watts,Model No. OV-490, Blue M. Electric Co., Blue Island, Ill.) at 280° F.and 320° F. and removed after ten minutes. The samples are allowed tocool and visually rated on a scale of 1 to 5 using AATCC Gray Scale.

Tetrapod Wear: ASTM D5251-92.

Hunter Green Purge Value: The additive concentrate systems of thepresent invention achieve a Hunter Green Purge Value ("HGPV") of betweenabout 0.10 to about 1.40 sec/cm³, more preferably, between about 0.50 toabout 1.40 sec/cm³, and most preferably between about 0.80 to about 1.05sec/cm³. In this regard, HGPV is the time, in seconds, per unit volume,in cubic centimeters, of the spinning system required for at least 90%of melt-spun Hunter Green nylon-6 filaments to achieve a CIE L* value ofabout 63 or greater at a system throughput of 217 g/min. Hunter Greennylon-6 polymer employed to determine HGPV was prepared as described inExample 10 below.

Example 1

Dispersant-coated pigment particles were prepared using the componentsnoted in Table A below. The components were blended using a high sheardissolver type mixer. A water soluble polyamide dispersant polymer (C-68manufactured by BASF Corporation in accordance with U.S. Pat. No.3,846,507 except that poly(ε-caprolactam) was used as a startingmaterial instead of ε-caprolactam) was first dissolved in water toprepare a 25 percent stock solution. Pigment dispersions were thenbead-milled with 2 mm glass beads for three passes through the mill andwere thereafter spray-dried. The dispersions were spray-dried using aNiro FSD-Pilot unit, which had a 1.5 meter diameter, 0.8 meters cylinderheight, 40° cone, and a fluidized bed collector at the bottom of thechamber. Dispersions were fed into the dryer with a two-fluid,externally-mixed nozzle. The spray-dryer was run with 253°-263° C. inletand 67°-103° C. outlet temperatures. The spray-dried powder tended to bedusty, and thus a fluidized bed collector was used to increaseagglomerate size and thereby reduce the dust.

                  TABLE A    ______________________________________                  % Pigment in                             % Dispersant in                  Aqueous    Aqueous    Pigment       Dispersion Dispersion    ______________________________________    Inorganic Yellow                  32.5       13.0    Organic Blue  20.0       15.0    Organic Red   20.0       15.0    Inorganic Tan 30.0       12.0    Organic Green 25.0       12.5    Organic Black 20.0       15.0    White/Stabilizer                  32.5       13.0    ______________________________________

Example 2

Example 1 was repeated except that a water-dispersible polyester (LB-100from Eastman Chemical Products, Inc.) was used as the dispersant polymerin the amounts noted in Table B below. Unlike Example 1 above, alldispersions according to this Example 2 contained 5.0% of apolyoxypropylene-polyoxyethylene block copolymer surfactant (Pluronic®25R2 surfactant from BASF Corporation). Spray-dried dispersions usingLB-100 as the dispersant were not dusty, and were prepared using theNiro spray-dryer which was not equipped with a fluidized bed collector.The Niro spray dryer was run with 220° C. inlet and 80°-95° C. outlettemperatures. These dispersions were fed into a rotary wheel typeatomizer running at 18,500 rpm.

                  TABLE B    ______________________________________                  % Pigment in                             % Dispersant in                  Aqueous    Aqueous    Pigment       Dispersion Dispersion    ______________________________________    Organic Blue  27.5       20.6    Organic Red   27.5       20.6    Inorganic Tan 32.5       13.0    Organic Green 32.5       24.7    Organic Black 25.0       18.7    White         40.0       16.0    White/Stabilizer                  40.0       16.0    ______________________________________

Example 3

The additive concentrate pastes in Table C below were prepared by firstmelting at 150° C. 50-60% of the required copolyamide carrier polymer(Vestamelt 722 from Huls America Inc.). The spray-dried powders obtainedaccording to Example 1 above were then bag-blended in desired ratios toachieve desired final colors and stirred into the molten carrierpolymer. The balance of the carrier polymer needed was then added andstirred into the concentrate blend formulation. The spray-dried powderstended to form large agglomerates which did not disperse withoutextended agitation. Thus, the blends were stirred overnight(approximately 10 to 12 hours) prior to yarn extrusion.

The white/stabilizer pigments used in the blended pigment ratios for allfinal colors, except Gray and Light Gray, were not the spray driedcoated pigments obtained according to Example 1. Instead, thewhite/stabilizer pigments were compounded with Vestamelt 722 polymerusing a vented twin screw compounding extruder to obtain chipconcentrates having 25 wt. % of white pigment and 25 wt. % stabilizer.The chip concentrates of such white/stabilizer pigments were thenblended in desired ratios with certain of the spray-dried pigmentsobtained in Example 1 to achieve the final colors noted below in TableC.

                  TABLE C    ______________________________________                 Total % Pigment in    Final Color  Paste    ______________________________________    Light Gray   13.9    Gray         9.3    Black        20.4    Light Green  20.0    Purple       25.3    Blue         19.0    Light Tan    19.8    Mauve        18.7    Green        19.0    Brown        19.7    ______________________________________

Example 4

The additive concentrate pastes in Table D below were prepared followingthe procedures of Example 3 above, except that the spray-dried powdersobtained from Example 2 were used, and the carrier was polycaprolactone.Unlike Example 3, no compounded chips of white/stabilizer pigments wereused.

                  TABLE D    ______________________________________                         Total % Pigment    Final Color          in Paste    ______________________________________    Light Gray           37.0    Gray                 37.8    Black                34.0    Light Green          39.0    Purple               35.5    Blue                 34.8    Light Tan            35.0    Mauve                30.5    Green                34.9    Brown                37.7    ______________________________________

Example 5

A Barmag 6E extruder was used for filament yarn extrusion with theadditive concentrate pastes in Table C being fed downstream of theextruder at around 150° C. in desired ratios to achieve the filamentcolor noted below in Table E. The resulting melt-spun filament yarnswere 6-hole pentagonal cross-section, 715+/-15 denier, and 14filaments/end. Eight ends of these undrawn yarns were combined duringdraw texturing to prepare 2250/112 denier yarns which were then two-plycable-twisted to make 4500/224 denier carpet yarns. The carpet yarnswere then tufted into 1/10 gauge, 26 ounces/square yard, 3/16" pileheight level loop carpets.

The carpets were then tested to determine various physical propertiesusing the testing methods and techniques described previously. Theresults of such testing are tabulated below in Tables 1-4 and arepresented in comparison to carpets formed of "control" filaments ofmatching color. The "control" filaments were made using conventionalcompounded pigment chips which were melt-blended with the polymeric hostchip in an extruder, with the melt-blend then being fed to thespinneret.

                  TABLE E    ______________________________________               Additive Concentrate                              % Additive               Paste Components Other                              Concentrate    Final Color               Than Stabilizer                              Paste in Filament    ______________________________________    Light Gray black, white, green, blue                              1.4    Gray       black, white, blue, red                              2.6    Black      black, white   3.8    Light Green               black, white, green, tan                              1.4    Purple     black, white, blue, red                              2.6    Blue       black, white, blue, red                              2.8    Light Tan  black, green, tan                              1.7    Mauve      black, blue, red                              2.8    Green      black, green, blue                              4.2    Brown      black, white, red, tan                              6.5    ______________________________________

                  TABLE 1    ______________________________________    Carpet physical properties after ultraviolet exposure.    Test samples made with C-68              Yarn Degradation                            Colorfastness              Pounds Break Strength                            Visual Ratings (1-5)                Ori-   100    200  300  100  200  300    Sample      ginal  hours  hours                                   hours                                        hours                                             hours                                                  hours    ______________________________________    TAN.sub.-- CTRL.sub.-- A                35.5   33.8   34.4 32.5 5    4-5  4-5    TAN.sub.-- V722                34.8   34.3   32.65                                   33.15                                        5    4    3-4    LT.sub.-- GRAY.sub.--                34.3   35.1   35.3 33.62                                        4-5  3-4  3    CTRL.sub.-- A    LT.sub.-- GRAY.sub.-- V722                35.9   32.4   32.85                                   31.7 4-5  3    2-3    LT.sub.-- GREEN.sub.--                36     34.8   35.3 34.2 5    4    3-4    CTRL.sub.-- A    LT.sub.-- GREEN.sub.-- V722                33.1   33     32   33.05                                        5    4-5  4-5    GRAY.sub.-- CTRL.sub.-- A                35.93  34.3   32.2 30.35                                        4-5  3-4  3-4    GRAY.sub.-- V722                33.3   31.9   30.15                                   29.85                                        5    4    3-4    BLACK.sub.-- CTRL.sub.-- A                33.05  30.6   28.2 26.55                                        5    5    4-5    BLACK.sub.-- V722                31.9   30.9   30.81                                   31.11                                        5    5    5    BROWN.sub.-- CTRL.sub.-- A                34.93  33.8   33.22                                   31.87                                        5    5    4-5    BROWN.sub.-- V722                31.64  31.1   30.7 31.31                                        5    5    4-5    GREEN.sub.-- CTRL.sub.-- A                34.48  31.7   33   32.76                                        5    5    5    GREEN.sub.-- V722                33.7   32.3   32.33                                   31.72                                        5    4-5  4-5    BLUE.sub.-- CTRL.sub.-- A                33.96  32.5   31.55                                   30.68                                        5    4-5  4-5    BLUE.sub.-- V722                33.6   32.3   31.2 31.8 5    4-5  4-5    PURPLE.sub.-- CTRL.sub.-- A                33.73  31.3   27.25                                   25.82                                        5    5    4-5    PURPLE.sub.-- V722                31.98  32.2   30.38                                   30.28                                        5    5    4-5    MAUVE.sub.-- CTRL.sub.-- A                33.8   33.4   30.8 28.75                                        5    5    4-5    MAUVE.sub.-- V722                32.2   30.9   29.9 27.35                                        5    5    4-5    ______________________________________

                  TABLE 2    ______________________________________    Carpet visual ratings after Taber wear, crock testing, and bleach    exposure.    Test samples made with C-68               Taber Abrasion               Test               Grams               Weight Loss               After:              Exposure               1000  2000    Crocking  to 50%               cycles                     cycles  Dry    Wet  Bleach    ______________________________________    TAN.sub.-- CTRL.sub.-- A                 0.077   0.122   5    5    4    TAN.sub.-- V722                 0.0592  0.1069  5    5    4-5    LT.sub.-- GRAY.sub.-- CTRL.sub.-- A                 0.0841  0.1179  5    5    4-5    LT.sub.-- GRAY.sub.-- V722                 0.0303  0.0587  5    5    3-4    LT.sub.-- GREEN.sub.-- CTRL.sub.-- A                 0.0793  0.1138  5    5    4-5    LT.sub.-- GREEN.sub.-- V722                 0.0666  0.0987  5    5    5    GRAY.sub.-- CTRL.sub.-- A                 0.0448  0.0845  5    5    4-5    GRAY.sub.-- V722                 0.0792  0.1312  5    5    4-5    BLACK.sub.-- CTRL.sub.-- A                 0.0594  0.0847  5    5    5    BLACK.sub.-- V722                 0.05    0.0968  5    5    4-5    BROWN.sub.-- CTRL.sub.-- A                 0.0461  0.0853  5    5    4-5    BROWN.sub.-- V722                 0.0578  0.1013  5    5    4-5    GREEN.sub.-- CTRL.sub.-- A                 0.0513  0.0963  5    5    4-5    GREEN.sub.-- V722                 0.0713  0.1153  5    5    4-5    BLUE.sub.-- CTRL.sub.-- A                 0.0797  0.1213  5    5    4    BLUE.sub.-- V722                 0.077   0.1139  5    5    4-5    PURPLE.sub.-- CTRL.sub.-- A                 0.0616  0.0998  5    5    5    PURPLE.sub.-- V722                 0.0957  0.14    5    5    4-5    MAUVE.sub.-- CTRL.sub.-- A                 0.0263  0.0471  5    5    4-5    MAUVE.sub.-- V722                 0.0392  0.0879  5    5    4-5    ______________________________________

                  TABLE 3    ______________________________________    Carpet visual ratings after ozone and nitrogen oxides exposure.    Test samples made with C-68               Visual Grades After                           Visual Grades After               Exposure to Ozone                           Exposure to NO2               3 cycles                      8 cycles 3 cycles 8 cycles    ______________________________________    TAN.sub.-- CTRL                 4-5      4-5      4-5    4-5    TAN.sub.-- V722                 4-5      4-5      4-5    4    LT.sub.-- GRAY.sub.-- CTRL                 4-5      4        3-4    3    LT.sub.-- GRAY.sub.-- V722                 4-5      4        3-4    3    LT.sub.-- GREEN.sub.-- CTRL                 5        5        4-5    4    LT.sub.-- GREEN.sub.-- V722                 5        4-5      4-5    4    GRAY.sub.-- CTRL                 4-5      4-5      5      4-5    GRAY.sub.-- V722                 4-5      4        4-5    3-4    BLACK.sub.-- CTRL                 5        4-5      5      5    BLACK.sub.-- V722                 5        4-5      5      5    BROWN.sub.-- CTRL                 5        4-5      5      4-5    BROWN.sub.-- V722                 5        4-5      5      4-5    GREEN.sub.-- CTRL                 5        5        5      4-5    GREEN.sub.-- V722                 5        5        4-5    4-5    BLUE.sub.-- CTRL                 5        4-5      4-5    4    BLUE.sub.-- V722                 5        4-5      4-5    4-5    PURPLE.sub.-- CTRL                 5        4-5      5      4-5    PURPLE.sub.-- V722                 5        5        5      5    MAUVE.sub.-- CTRL                 5        4-5      5      5    MAUVE.sub.-- V722                 5        5        5      4-5    ______________________________________

                  TABLE 4    ______________________________________    Carpet visual ratings after exposure to dry heat and Tetrapod wear.    Test samples made with C-68                Dry Heat Exposure                            500 K in Tetrapod                280° F.                       320° F.                                Stair   End    ______________________________________    TAN.sub.-- CTRL.sub.-- A                  5        4-5      4     4    TAN.sub.-- V722                  5        4-5      3     3-4    LT.sub.-- GRAY.sub.-- CTRL.sub.-- A                  4-5      4        3-4   3-4    LT.sub.-- GRAY.sub.-- V722                  4        3        3-4   4    LT.sub.-- GREEN.sub.-- CTRL.sub.-- A                  4-5      4        3-4   3-4    LT.sub.-- GREEN.sub.-- V722                  4-5      4        3     3-4    GRAY.sub.-- CTRL.sub.-- A                  5        4-5      4     4    GRAY.sub.-- V722                  4-5      3-4      3     3-4    BLACK.sub.-- CTRL.sub.-- A                  5        4-5      4     4-5    BLACK.sub.-- V722                  5        5        4     4    BROWN.sub.-- CTRL.sub.-- A                  5        4-5      3-4   4    BROWN.sub.-- V722                  5        4-5      4     4    GREEN.sub.-- CTRL.sub.-- A                  5        4-5      2-3   3-4    GREEN.sub.-- V722                  5        4-5      2     3    BLUE.sub.-- CTRL.sub.-- A                  5        4-5      3-4   4    BLUE.sub.-- V722                  5        4-5      3     3-4    PURPLE.sub.-- CTRL.sub.-- A                  5        4-5      3-4   4    PURPLE.sub.-- V722                  5        4-5      3-4   3-4    MAUVE.sub.-- CTRL.sub.-- A                  5        4-5      4     4    MAUVE.sub.-- V722                  5        4-5      3-4   4    ______________________________________

Example 6

Example 5 was repeated except that the additive concentrate pastes ofTable D were fed at the extruder throat at ambient temperature (about20° C. ). The paste components and the amount of paste in the filamentsare noted below in Table F. The resulting filaments were formed intocarpets and tested similar to Example 5. The results appear in Tables5-8 below.

                  TABLE F    ______________________________________               Additive Concentrate                              % Additive               Paste Components Other                              Concentrate    Final Color               Than Stabilizer                              Paste in Filament    ______________________________________    Light Gray black, white, green, blue                              0.6    Gray       black, white, blue, red                              0.7    Black      black, white   2.2    Light Green               black, white, green, tan                              0.8    Purple     black, white, blue, red                              2.0    Blue       black, white, blue, red                              1.6    Light Tan  black, green, tan                              1.0    Mauve      black, blue, red                              1.9    Green      black, green, blue                              2.2    Brown      black, white, red, tan                              3.6    ______________________________________

                  TABLE 5    ______________________________________    Carpet physical properties after ultraviolet exposure.    Test samples made with LB-100              Yarn Degradation                            Colorfastness              Pounds Break Strength                            Visual Ratings (1-5)                Ori-   100    200  300  100  200  300    Sample      ginal  hours  hours                                   hours                                        hours                                             hours                                                  hours    ______________________________________    TAN.sub.--  36.06  36     35.2 32.85                                        5    4-5  4-5    CTRL.sub.-- B    TAN.sub.-- PCL                35.08  34.45  35   33.4 5    4-5  4-5    LT.sub.-- GRAY.sub.--                36.13  35.98  35.8 34.8 3    2-3  2-3    CTRL.sub.-- B    LT.sub.-- GRAY.sub.-- PCL                35.97  35.95  34.35                                   33.95                                        3-4  2-3  2-3    LT.sub.-- GREEN.sub.--                36.7   36.15  35.1 32.85                                        4-5  4    3    CTRL.sub.-- B    LT.sub.-- GREEN.sub.-- PCL                35.93  35.01  34.05                                   32.95                                        5    4-5  4    GRAY.sub.-- CTRL.sub.-- B                36.43  36.03  35.1 35.2 5    5    4-5    GRAY.sub.-- PCL                35.95  34.71  32.25                                   31.2 5    4    4    BLACK.sub.-- CTRL.sub.-- B                32.56  30     28.21                                   22.96                                        5    4-5  4-5    BLACK.sub.-- PCL                31.25  30.85  30.9 28.08                                        5    4-5  4-5    GREEN.sub.-- CTRL.sub.-- B                33.15  32.05  31.6 29.8 5    4-5  4-5    GREEN.sub.-- PCL                32.83  32.41  32.5 30.45                                        5    4-5  4-5    BLUE.sub.-- CTRL.sub.-- B                34.5   32.8   31.67                                   29.5 4-5  4-5  4    BLUE.sub.-- PCL                34.78  33.7   34.21                                   32.35                                        5    4-5  4-5    PURPLE.sub.-- CTRL.sub.-- B                33.52  32.33  27.95                                   24.1 5    4-5  4    PURPLE.sub.-- PCL                33.68  32.55  32.25                                   29.25                                        4-5  4-5  4    ______________________________________

                  TABLE 6    ______________________________________    Carpet visual ratings after Taber wear, crock testing, and bleach    exposure.    Test samples made with LB-100               Taber Abrasion               Test               Grams               Weight Loss               After:              Exposure               1000  2000    Crocking  to 50%               cycles                     cycles  Dry    Wet  Bleach    ______________________________________    TAN.sub.-- CTRL.sub.-- B                 0.033   0.0661  5    5    5    TAN.sub.-- PCL                 0.0252  0.0487  5    5    4-5    LT.sub.-- GRAY.sub.-- CTRL.sub.-- B                 0.0365  0.0664  5    5    3-4    LT.sub.-- GRAY.sub.-- PCL                 0.0018  0.0234  5    5    3-4    LT.sub.-- GREEN.sub.-- CTRL.sub.-- B                 0.0186  0.0394  5    5    4-5    LT.sub.-- GREEN.sub.-- PCL                 0.013   0.0426  5    5    5    GRAY.sub.-- CTRL.sub.-- B                 0.0427  0.0529  5    5    4-5    GRAY.sub.-- PCL                 0.0297  0.0608  5    5    4    BLACK.sub.-- CTRL.sub.-- B                 0.0905  0.1216  5    5    4-5    BLACK.sub.-- PCL                 0.1323  0.1898  5    5    4-5    GREEN.sub.-- CTRL.sub.-- B                 0.0561  0.0874  5    5    4-5    GREEN.sub.-- PCL                 0.0392  0.0668  5    5    4-5    BLUE.sub.-- CTRL.sub.-- B                 0.065   0.0987  5    5    4-5    BLUE.sub.-- PCL                 0.0693  0.1297  5    5    4-5    PURPLE.sub.-- CTRL.sub.-- B                 0.0719  0.1082  5    5    4    PURPLE.sub.-- PCL                 0.0887  0.1289  5    5    4    ______________________________________

                  TABLE 7    ______________________________________    Carpet visual ratings after ozone and nitrogen oxides exposure.    Test samples made with LB-100               Visual Grades After                           Visual Grades After               Exposure to Ozone                           Exposure to NO2               3 cycles                      8 cycles 3 cycles 8 cycles    ______________________________________    TAN.sub.-- CTRL.sub.-- B                 4-5      4        4-5    4    TAN.sub.-- PCL                 4-5      4-5      4-5    4-5    LT.sub.-- GRAY.sub.-- CTRL.sub.-- B                 4-5      4        4      3    LT.sub.-- GRAY.sub.-- PCL                 4        3-4      4      3-4    LT.sub.-- GREEN.sub.-- CTRL.sub.-- B                 4-5      4-5      4      4    LT.sub.-- GREEN.sub.-- PCL                 4-5      4-5      4-5    4-5    GRAY.sub.-- CTRL.sub.-- B                 4-5      4-5      4      4    GRAY.sub.-- PCL                 4-5      4-5      4-5    4-5    BLACK.sub.-- CTRL.sub.-- B                 5        4-5      5      4-5    BLACK.sub.-- PCL                 5        4-5      5      4-5    GREEN.sub.-- CTRL.sub.-- B                 5        4-5      5      4-5    GREEN.sub.-- PCL                 4-5      4        5      4    BLUE.sub.-- CTRL.sub.-- B                 4-5      4        4-5    4    BLUE.sub.-- PCL                 4-5      4        4-5    4-5    PURPLE.sub.-- CTRL.sub.-- B                 4-5      4        4-5    4    PURPLE.sub.-- PCL                 4-5      4        4-5    4    ______________________________________

                  TABLE 8    ______________________________________    Carpet visual ratings after exposure to dry heat and Tetrapod wear.    Test Samples made with LB-100                             500 K in                 Dry Heat Exposure                             Tetrapod                 280° F.                        320° F.                                 Stair   End    ______________________________________    TAN.sub.-- CTRL.sub.-- B                   4-5      4        3     3    TAN.sub.-- PCL 4-5      4        3     3    LT.sub.-- GRAY.sub.-- CTRL.sub.-- B                   4-5      3        3     3    LT.sub.-- GRAY.sub.-- PCL                   4-5      3        3     3    LT.sub.-- GREEN.sub.-- CTRL.sub.-- B                   4-5      3-4      3     3    LT.sub.-- GREEN.sub.-- PCL                   4-5      4        3     3    GRAY.sub.-- CTRL.sub.-- B                   4-5      4        3     3    GRAY.sub.-- PCL                   4-5      4        3     3    BLACK.sub.-- CTRL.sub.-- B                   5        5        3-4   4    BLACK.sub.-- PCL                   5        5        3-4   3-4    GREEN.sub.-- CTRL.sub.-- B                   5        4-5      2-3   3-4    GREEN.sub.-- PCL                   5        4-5      3-4   3-4    BLUE.sub.-- CTRL.sub.-- B                   5        4-5      3-4   3-4    BLUE.sub.-- PCL                   4-5      4        3-4   3-4    PURPLE.sub.-- CTRL.sub.-- B                   4-5      4        3-4   3-4    PURPLE.sub.-- PCL                   4-5      4        3-4   3-4    ______________________________________

The data in Tables 1-8 above demonstrate that the performance propertiesof carpet yarns made from pigmented filaments of this invention arecomparable to carpet yarns which are colored according to theconventional practice of melt-blending pigmented chips with base polymerchips. It is surprising that the incorporation of the lowmolecular-weight polymer as the carrier in the dispersible additive didnot affect either the breaking strength or elongation of the pigmentedfilaments of this invention when compared to conventional melt-coloredfilaments.

Example 7

A tan additive concentrate paste was formed by direct blending of 40 wt.% tan pigment particles, 8 wt. % of polyethylene glycol p-octyl phenylether (Triton X-100) dispersant, and 52 wt. % polycaprolactone. Theresulting additive concentrate paste was preheated to approximately 140°C. and exhibited a viscosity of between 2000 to 4000 cP. The paste waspumped directly into a spin pack assembly at a location downstream ofthe polymer filter but upstream of the spinneret orifices (58 holeasymmetrical trilobal). The additive concentrate paste was mixed withthe nylon-6 polymeric host material within the spin pack assembly at arate of between about 6.0 g/min (to obtain about 0.8-1.1 wt. % pigmentin the resulting melt-spun filaments) to about 7.3 g/min (to obtainabout 1.1-1.5 wt. % pigment in the resulting melt-spun filaments). Theresulting melt-spun filaments had a uniformly colored appearance alongthe lengthwise extent as viewed with an unaided eye. Microscopic viewsof filament cross-sections revealed that substantially homogenous tosomewhat striated mixing had occurred in dependence upon the injectionrate of the additive paste.

Example 8

Example 2 was repeated to produce the dispersible additives noted inTable F below:

                  TABLE F    ______________________________________                 % Pigment in                            % Dispersant in                 Aqueous    Aqueous    Pigment      Dispersion Dispersion    ______________________________________    Anatase TiO.sub.2                 37.5       15.0    Red 149      27.5       20.6    Green 7      27.5       20.6    Black 6      25.0       18.7    Blue 15      27.5       20.6    Brown 11     32.5       13.0    Red 101      20.0       13.0    Red 179      35.0       17.5    Violet 29    20.0       12.0    Red 101      30.0       11.2    Brown 24     32.5       13.0    Blue 60      25.0       12.5    Red 202      27.5       20.6    ______________________________________

The additive concentrate pastes in Table G below were prepared followingthe procedures of Example 3 above, except that the spray-dried powdersof Table F above were used, and the carrier was polycaprolactone.

                  TABLE G    ______________________________________                  % Spray Dried    Pigment       Powder in Paste    ______________________________________    Anatase TiO.sub.2                  57.21    Red 149       57.44    Green 7       57.44    Black 6       57.44    Blue 15       57.44    Brown 11      57.21    Red 101       57.21    Red 179       52.50    Violet 29     57.44    Red 101       57.21    Brown 24      57.21    Blue 60       57.21    Red 202       57.21    ______________________________________

Example 9

In order to investigate the effectiveness of employing spray-driedadditive powders in accordance with the present invention, an aqueousC.I. pigment black 6 dispersion using LB-100 as the dispersant wasball-milled in a Chicago Boiler five-liter horizontal Dyno-Mill loadedwith 4.25 liters of 1.0-1.3 mm glass beads and running at 1705 rpm. Theaqueous dispersion was spray-dried in a Niro Utility Spray Dryer havinga rotary atomizer running at 24,350 rpm. The inlet air temperature was220° C. at about 220 cfm. The dispersion feed rate was adjusted toachieve a discharge air temperature of 90° C. The resulting spray drieddispersible pigment particles were then blended with polycaprolactone asthe carrier to form a paste such that 20 wt. % of the black pigment waspresent in the resulting paste. The viscosity (centipoise) of the pastewas then investigated as a function of shear rate (sec⁻¹) with theresults being present in Table H (the "Spray Dry/Disperse" sample).

By way of comparison, 20 wt. % of the same black pigment (C.I. pigmentblack 6) was dispersed directly in polycaprolactone carrier without thebenefit of being spray dried with LB-100 dispersant. The viscosity(centipoise) of the dispersion was also investigated as a function ofshear rate (sec⁻¹) with the results being present in Table H below (the"Direct Disperse" sample).

                  TABLE H    ______________________________________    Spray Dry/Disperse     Direct Disperse    Shear Rate             Viscosity     Shear Rate                                    Viscosity    (sec.sup.-1)             (cps)         (sec.sup.-1)                                    (cps)    ______________________________________    1.4      8148          0.6      50130    2.4      5729          1.2      31290    4.2      4303          3.0      14940    7.3      3466          6.0      11440    12.6     2744          12.0      6291    21.8     2385          24.0      4825    ______________________________________

The data above demonstrate that, at the same pigment loadings in thedispersions, significantly lower viscosities ensue at the same shearrates for spray-dried pigments. Thus, at comparable shear rate, greaterpigment loadings are possible for the spray-dried pigments withoutadversely affecting processing conditions. As a result, therefore, thedispersible additive pastes of this invention which include spray-driedpigments can be incorporated into the host polymeric materials in lesseramounts as compared to direct dispersed pigments in order to achievecomparable pigment properties.

Example 10--Hunter Green Purge Values

Green 7, Black 6, Blue 15 and White (anatase TiO₂) pastes were preparedaccording to Example 8, above. Specifically, batches of 200 pounds ofeach paste were prepared using a mixing profile which began with 30seconds at a tip speed of 10 m/sec, followed by 3 minutes at 20 m/sec,followed by a discharge period of 45 seconds at 6-8 m/sec.

A copper stabilizer paste was also prepared by charging the mixer with125 pounds of copper stabilizer and 125 pounds of polycaprolactone. Themixing profile for the copper stabilizer paste began with 10 m/sec tipspeed for 2 minutes followed by 10 minutes at 40 m/sec. The copperstabilizer paste was allowed to cool to 125° F. by dropping the mixertip speed to 10 m/sec and circulation of cooling water through the mixerjacket. After the temperature had dropped, the copper stabilizer pastewas discharged at 6-8 m/sec tip speed.

Hunter Green color pastes were prepared by charging the followingcomponents and polycaprolactone liquid polymer into a Henschel FM-200high intensity mixer (all percentages being the weight percent of thecomponents in the paste blend):

(1) Copper Stabilizer Paste: 0.5-1.0 wt. %

(2) Green 7 Paste: 50-60 wt. %

(3) Black 6 Paste: 5-10 wt. %

(4) Blue 15 Paste: 10-15 wt. %

(5) White (anatase TiO₂) Paste: Balance to bring Hunter Green pasteblend to 100 wt. %

In order to determine the HGPV, the Hunter Green paste is injected intothe host polymer (e.g., nylon 6) at 2.7 wt. % to achieve Hunter Greenfilaments. Injection of the Hunter Green paste is stopped and the timein seconds per unit spinning system volume, in cubic centimeters, isdetermined when at least 90% of the filaments achieve a CIE L* value of63 or greater at a system throughput of 217 g/min.

What is claimed is:
 1. An additive-containing thermoplastic polymercomposition comprising:(a) a thermoplastic melt-spinnable polymeric hostmaterial which is at least one non-water soluble polymer selected fromthe group consisting of poly(hexamethylene adipamide), polycaprolactam,polyamides formed from bis(4-aminocyclohexyl) methane with linearaliphatic dicarboxylic acids containing 9, 10 and 12 carbon atoms,poly(terephthalic acid) and copolymers thereof, polyethylene,polypropylene and polyurethanes, and (b) an additive system dispersedthroughout said polymeric host material, wherein said system comprises(1) a water-soluble sulphonated polyamide or polyester dispersantpolymer, (2) solid pigment particles coated by said dispersant polymerso as to form solid dispersant-coated pigments, and (3) a liquidnonaqueous polymeric carrier selected from polyamides and polyesterswhich are liquid at a temperature less than about 200° C. and in whichsaid solid dispersant-coated pigments are dispersed.
 2. The compositionas in claim 1, wherein the pigments are colorants, stabilizers,delusterants, flame retardants, fillers, antimicrobial agents,antistatic agents, optical brighteners, extenders, or processing aids.3. The composition as in claim 1, wherein the pigments are colorantparticles having a mean particle size of less than 10 μm.
 4. Thecomposition as in claim 1, wherein the pigments are present in an amountbetween about 5 to about 75% by weight of said additive system.
 5. Thecomposition of claim 1, wherein said pigments have an average particlesize of about 1 μm or less.
 6. The composition of claim 1 or 5, whereinthe pigments are spray-dried pigments.
 7. A method of making additivecontaining thermoplastic polymer compositions comprising the stepsof:(i) forming a dispersible additive system by (1) coating solidpigment particles with a water-dispersible sulphonated polyamide orpolyester dispersant polymer so as to form solid dispersant-coatedpigment particles, and thereafter (2) introducing said soliddispersant-coated pigment particles into a liquid nonaqueous polyamideor polyester polymeric carrier which is liquid at a temperature lessthan about 200° C.; and then subsequently (ii) dispersing the additivesystem into a melt of a thermoplastic polymeric host material to form anadditive-containing thermoplastic composition, wherein the thermoplasticpolymer host material is at least one non-water-soluble polymer selectedfrom the group consisting of poly(hexamethylene adipamide),polycaprolactam, polyamides formed from bis(4-aminocyclohexyl) methanewith linear aliphatic dicarboxylic acids containing 9, 10 and 12 carbonatoms, poly(terephthalic acid) and copolymers thereof, polyethylene,polypropylene and polyurethanes.
 8. The method of claim 7, wherein priorto step (i) there are practiced the steps of:(a) forming an aqueousdispersion comprised of the solid pigment particles and thewater-soluble dispersant polymer; and then (b) spray-drying the aqueousdispersion so as to obtain the dispersant-coated pigment particles. 9.The method of claim 7 or 8, comprising mixing the spray-drieddispersant-coated pigment particles with the polymeric carrier prior tostep (ii).
 10. The method of claim 9, wherein the spray drieddispersant-coated pigment has an average particle size of about 5 μm orgreater prior to being blended with the polymeric host materialaccording to step (ii), and wherein the dispersant-coated pigment has anaverage particle size of about 1 μm or less after dispersion into thepolymeric host material according to step (ii).
 11. The method of claim7, wherein the pigments are colorants, stabilizers, delusterants, flameretardants, fillers, antimicrobial agents, antistatic agents, opticalbrighteners, extenders, or processing aids.
 12. The method of claim 7,wherein the polymeric carrier is polycaprolactone.
 13. The method ofclaim 7, wherein step (a) includes spray-drying said pigments and saiddispersant polymer so as to form spray-dried, dispersant-coated pigmentparticles.
 14. A colored thermoplastic nylon composition comprising athermoplastic nylon host material, and a colorant additive systemdistributed throughout said nylon host material so as to impart a colorthereto, wherein said colorant additive system comprises (1) solidcolorant pigment particles, (2) a water-soluble sulphonated polyamide orpolyester dispersant polymer coated on said colorant pigment particlesso as to form dispersant-coated colorant pigment particles, and (3) anonaqueous polycaprolactone carrier which is liquid at 20° C. and inwhich said dispersant-coated colorant particles are dispersed.
 15. Thecomposition as in claim 14, wherein the polymeric host material isnylon-6.
 16. The composition as in claim 14, wherein the colorantpigment particles have a mean particle size of less than 10 μm.
 17. Thecomposition as in claim 14, wherein the colorant pigment particles arepresent in an amount between about 5 to about 75% by weight of saidcolorant additive system.
 18. The composition of claim 14, wherein saidcolorant pigment particles have an average particle size of about 1 μmor less distributed throughout said host polymer.
 19. The composition asin claim 14, wherein said dispersant-coated colorant pigment particlesare spray-dried.
 20. An additive-containing thermoplastic polymercomposition comprising.(a) a thermoplastic, melt-spinnable polymerichost material, wherein said polymeric host material is at least onepolymer or copolymer selected from the group consisting ofpoly(hexamethylene adipamide), polycaprolactam, polyamides formed frombis(4-aminocyclohexyl) methane with linear aliphatic dicarboxylic acidscontaining 9, 10, and 12 carbon atoms, poly(terephthalic acid) andcopolymers thereof, polyethylene, polypropylene, and polyurethanes, and(b) a nonaqueous additive system dispersed throughout said polymerichost material, wherein said additive system comprises (1) solid pigmentparticles, (2) a dispersant coating said pigment particles so as to formdispersant-coated pigment particles, and (3) a polymeric carrierselected from polyamides and polyesters that are liquid below 200° C.and in which said dispersant-coated pigment particles are dispersed,wherein said dispersant is at least one selected from the groupconsisting of polyethylene glycol p-octyl phenyl ether,polyoxypropylene/ethylene block copolymers, alkoxylated diamines, sodiumlauryl sulfate and cationic dispersants.